Karlach says (approximately) "One more trip to Avernus. At least it's for a good cause." Helsik, the diabolist, also says you're going to Avernus - just replayed this yesterday.
On top of which, you get plenty of chances to view the landscape around Raphael's house, and it definitely does not look like Minauros.
Thanks! I did look outside the House to figure it out and it did look like Avernus (thought I admit I didn’t read what Minauros looks like to re-check EDIT: ah, it's the swampy one).
Now, I guess that settles it, and the coin/book might just be a slip or doesn’t really connect to the quest.
Again, thanks for the updated reply!
